gnome-session hard code freeze break request

[Ray Strode <halfline gmail com>]

Hey guys,

I shamefully forgot to push the gnome-session half of some shutdown
changes before the gnome-session release (I didn't have it staged in
my local branch like i thought I did apparently).  This means people
can't shutdown or logout their machines wth 2.91.92...

See https://bugzilla.gnome.org/show_bug.cgi?id=641375#c17 and the
latter comments

Okay to push this missing piece?